A SIM-only plan is a monthly mobile subscription without a bundled handset. You supply your own phone (either one you already own or a phone bought separately), and pay only for the network access — calls, texts, and data. SIM-only plans are typically $20–$40/month cheaper than equivalent plans that include a new handset.
Example: Spark "My Everything" $75/month plan includes a phone repayment of ~$35/month on a standard device. The same data/calls as SIM-only on Skinny costs ~$30/month. That's a $45/month saving — $540/year — for the same calls and data, using your existing phone. If your phone works fine, there's no reason to keep paying the handset component.
How SIM-Only Plans Work
- Buy a SIM card from your chosen provider (usually free or $2–$5 at supermarkets, dairies, provider stores)
- Insert into your phone — ensure your phone is unlocked (not locked to another network)
- Activate online and choose your monthly plan
- Pay monthly — direct debit or credit card
Is your phone locked? Phones bought on a plan from Spark, One NZ, or 2degrees may be locked to that network. You can usually request unlocking after 6–12 months (often free once the initial lock period passes). Check with your current provider.
Best SIM-Only Plans NZ 2026
Skinny Mobile — Best Value on Spark Network
| Plan | Cost | Data | Calls/Texts |
|---|---|---|---|
| Skinny $23/month | $23 | 3GB | Unlimited NZ |
| Skinny $30/month | $30 | 8GB | Unlimited NZ |
| Skinny $35/month | $35 | 15GB | Unlimited NZ |
| Skinny $40/month | $40 | 25GB | Unlimited NZ |
Skinny is consistently the cheapest SIM-only option on the Spark network. Identical rural coverage to Spark for $20–$30/month less.
2degrees — Best Data Value Overall
| Plan | Cost | Data | Calls/Texts |
|---|---|---|---|
| 2degrees $20/month | $20 | 2–3GB | Unlimited NZ |
| 2degrees $30/month | $30 | 8–10GB | Unlimited NZ |
| 2degrees $40/month | $40 | 20–25GB | Unlimited NZ |
| 2degrees $50/month | $50 | 40–50GB | Unlimited NZ |
2degrees often offers the most data per dollar in the market, particularly in the $30–$50 range. Their network is strong in cities and has improved significantly in regional/rural areas.
One NZ — Best 5G SIM-Only
| Plan | Cost | Data | Notes |
|---|---|---|---|
| One NZ $30/month | $30 | 5–8GB | Unlimited NZ calls/texts |
| One NZ $50/month | $50 | 30–40GB | 5G included |
| One NZ $60/month | $60 | 60GB | 5G included |
One NZ has good 5G coverage in major cities. If you have a 5G phone and live in an urban area, One NZ’s 5G SIM-only plans are worth comparing.
Spark — Best Rural SIM-Only
| Plan | Cost | Data | Notes |
|---|---|---|---|
| Spark $30/month | $30 | 5GB | Best rural coverage |
| Spark $55/month | $55 | 30GB | Unlimited calls/texts |
| Spark $75/month | $75 | 60–100GB | 5G included |
Spark is more expensive than Skinny for the same network — only choose Spark SIM-only over Skinny if you need specific Spark features (Spark Sport bundle, Spark Business support, etc.).
SIM-Only vs Handset Plan: The Real Cost
Here’s how the numbers work for someone buying a mid-range phone:
| Scenario | Monthly cost | 24-month cost |
|---|---|---|
| Spark plan with $800 phone (24 months) | ~$75/month (plan + phone repay) | $1,800 |
| Buy phone outright ($800) + Skinny $30/month SIM-only | $30/month after month 1 | $800 + $720 = $1,520 |
| Saving over 24 months | $280 |
If you already own a phone (no outright purchase needed):
- Spark plan with phone: $75/month × 24 = $1,800
- Skinny SIM-only: $30/month × 24 = $720
- Saving: $1,080 over 24 months
The saving is most dramatic when your current phone is already paid off and working fine.
Switching to SIM-Only: Is Your Number Portable?
Yes — your NZ mobile number is portable. You can keep your existing phone number when switching providers. The new provider handles the number transfer process (takes 1–2 business days typically).
You’ll need to unlock your phone if it’s locked to your current network. Ask your current provider — unlocking is usually free once any lock period has passed.